1.
Organelles help maintain proper functioning within a cell. Which of the following organelles helps control protein manufacturing?
Correct Answer
B. Ribosomes
Explanation
Ribosomes are the organelles responsible for protein manufacturing within a cell. They are involved in the process of translation, where genetic information from the DNA is used to synthesize proteins. Ribosomes can be found in both prokaryotic and eukaryotic cells and play a crucial role in maintaining proper cellular functioning by ensuring the production of proteins needed for various cellular processes.
2.
In 1927, the geneticist Hermann Muller exposed living fruit flies to X-rays. He found that the fruit flies' offspring displayed dramatic mutations. Muller concluded that the X-rays damaged chromosomes. What was the independent variable in Muller's experiment?
Correct Answer
A. The X-rays
Explanation
In Muller's experiment, the independent variable is the X-rays. This is because the X-rays were deliberately manipulated and controlled by Muller in order to observe their effects on the fruit flies and their offspring. The independent variable is the factor that is changed or manipulated by the researcher in an experiment to see its impact on the dependent variable, which in this case would be the mutations observed in the fruit flies' offspring.
3.
Alexis is curious about whether a relationship exists between the temperature of an aquarium's water and the number of times a fish's gills flap each minute. What is the first thing that the student should do?
Correct Answer
B. Make a hypothesis about the relationship between water temperature and the number of times a fish's gills flap each minute
Explanation
The first thing the student should do is make a hypothesis about the relationship between water temperature and the number of times a fish's gills flap each minute. This is because a hypothesis is a statement that predicts a relationship or outcome based on observations or previous knowledge. It will guide the student's research and help them design experiments to test their hypothesis.
4.
Tony observes that corn seedlings will bend toward a light source. He grows 150 corn seedlings. He then removes the tips from 50 seedlings, covers the tips of another 50 seedlings with aluminum foil, and leaves the last 50 seedlings alone. He puts all the seedlings near a strong light source and observes them for 3 days. Which hypothesis is Tony testing?
Correct Answer
D. If light does not reach the tip of a seedling, the seedling will not bend toward the light.
Explanation
Tony is testing the hypothesis that if light does not reach the tip of a seedling, the seedling will not bend toward the light. He conducts an experiment where he removes the tips from 50 seedlings, covers the tips of another 50 seedlings with aluminum foil, and leaves the last 50 seedlings alone. He then observes all the seedlings near a strong light source for 3 days. By comparing the growth and bending patterns of the different groups of seedlings, Tony can determine if the presence or absence of light at the tip affects the seedlings' ability to bend towards the light.
5.
Which of the following is an example of a qualitative observation?
Correct Answer
B. The names of chemicals found in one brand of diet soda
Explanation
The names of chemicals found in one brand of diet soda is an example of a qualitative observation because it involves the description or characteristics of the chemicals present in the soda. It does not involve numerical data or measurements, but rather focuses on the qualities or properties of the substances.
6.
Which of the following is not an observation about the image shown?
Correct Answer
C. The insect's pattern shows that it is poisonous.
Explanation
The given answer is "The insect's pattern shows that it is poisonous." This answer is not an observation about the image shown because the image does not provide any information about the insect's pattern indicating its toxicity. The image only shows the color and physical appearance of the insect, but does not provide any evidence or indication of its poisonous nature.
7.
The statement that a worm is 2 centimeters long is a(n)
Correct Answer
A. Observation
Explanation
The given statement that a worm is 2 centimeters long is an observation because it is a direct and factual statement based on what is directly observed or measured. It does not involve any speculation or interpretation, but rather presents a straightforward observation of the worm's length.
8.
An inference is
Correct Answer
A. A logical interpretation of data.
Explanation
An inference is a logical interpretation of data because it involves drawing conclusions or making predictions based on the information or evidence that is available. It requires analyzing the data and using reasoning to come to a logical conclusion. Inferences go beyond simple observations, which are just statements of what is directly observed, and they also do not necessarily involve numbers or calculations. Inferences are important in many fields, such as science and research, where they help to make sense of data and draw meaningful conclusions.
9.
To be useful in science, a hypothesis must be
Correct Answer
B. Testable
Explanation
A hypothesis must be testable in order to be useful in science. This means that it must be possible to design experiments or gather data that can either support or refute the hypothesis. If a hypothesis is not testable, it cannot be proven or disproven through scientific methods, and therefore it is not considered valid in the scientific community. A testable hypothesis allows scientists to conduct experiments and gather evidence to support or reject the hypothesis, ultimately contributing to the advancement of scientific knowledge.
10.
Which of the following statements about a controlled experiment is true?
Correct Answer
D. Only one variable is tested at a time.
Explanation
In a controlled experiment, only one variable is tested at a time. This is important because it allows researchers to determine the specific effect that the variable has on the outcome of the experiment. By keeping all other variables constant, any changes in the outcome can be attributed to the tested variable. This helps to ensure valid and reliable results.
11.
The process by which organisms keep their internal environment stable is called
Correct Answer
C. Homeostasis
Explanation
Homeostasis refers to the process by which organisms maintain a stable internal environment, despite external changes. It involves various physiological mechanisms that regulate temperature, pH levels, blood pressure, and other factors within a narrow range. This balance is crucial for the proper functioning of cells and organs. Development refers to the process of growth and maturation, differentiation refers to the specialization of cells, and evolution refers to the gradual change in species over time. However, none of these options accurately describe the process of maintaining internal stability, making homeostasis the correct answer.
12.
April wants to test how temperature affects germination (sprouting of a plant from a seed.) She is measuring temperature in degrees Celsius. Which should April measure to get the best results?
Correct Answer
C. The germination of plants from 100 seeds at 15 degrees Celsius, 100 seeds at 22 degrees Celsius, and 100 seeds at 29 degrees Celsius
Explanation
To get the best results, April should measure the germination of plants from 100 seeds at 15 degrees Celsius, 100 seeds at 22 degrees Celsius, and 100 seeds at 29 degrees Celsius. This allows her to compare the germination rates at three different temperatures, providing a more comprehensive understanding of how temperature affects germination. By including multiple temperature levels, April can identify any patterns or trends in germination based on temperature variations.
13.
A scientist who monitors drinking water supplies found the disease-causing organism Cryptosporidium parvum to be resistant to the common disinfectants chlorine and monochloramine. The scientist investigated whether chlorine dioxide would be more effective against C.parvum. She designed an experiment in which she added chlorine dioxide, monochloramine, and chlorine dioxide to separate water samples. She then tested the water for populations of C. parvum. Which hypothesis was the scientist most likely testing in this experiment?
Correct Answer
B. If chlorine dioxide is added to drinking waer, it will be more effective than either chlorine or monochloramine against C.parvum.
Explanation
The scientist is testing the hypothesis that chlorine dioxide will be more effective than chlorine or monochloramine against C.parvum. This is evident from the design of the experiment where chlorine dioxide, monochloramine, and chlorine dioxide were added to separate water samples and then tested for populations of C.parvum. The other hypotheses mentioned in the options do not align with the experiment setup and the objective of testing the effectiveness of chlorine dioxide.
14.
Which of the following is NOT a goal of science?
Correct Answer
C. To establish a collection of unchanging truths
Explanation
The goal of science is to investigate and explain the natural world, to explain events in the natural world, and to make useful predictions. However, it is not the goal of science to establish a collection of unchanging truths. Science is a dynamic and evolving field that is constantly updating and revising its understanding of the natural world based on new evidence and discoveries. Therefore, the idea of "unchanging truths" goes against the fundamental principles of science.
15.
Science differs from other disciplines such as history and art because science relies on
Correct Answer
B. Testing explanations
Explanation
Science differs from other disciplines such as history and art because it relies on testing explanations. While history and art may focus on interpretation and subjective analysis, science is based on empirical evidence and the scientific method. Testing explanations allows scientists to gather data and evidence to support or refute hypotheses, leading to a more objective and reliable understanding of the natural world.
16.
Scientists will never know for sure why dinosaurs became extinct. Therefore, scientists should
Correct Answer
C. Continue to learn as much as they can about dinosaur extinction
Explanation
The given answer is "continue to learn as much as they can about dinosaur extinction". This is because although scientists may never know for sure why dinosaurs became extinct, it is still important to gather as much information and knowledge as possible about the extinction event. By studying dinosaur extinction, scientists can gain insights into the Earth's history, climate changes, and potential factors that may have contributed to the extinction. This knowledge can also help in understanding and predicting future mass extinctions and their impact on the planet.
17.
Science is best described as
Correct Answer
B. A way of knowing
Explanation
Science is best described as a way of knowing because it is a systematic approach that uses observation, experimentation, and logical reasoning to understand and explain the natural world. It involves generating hypotheses, testing them through experiments, and analyzing the results to draw conclusions. Science is not just a collection of facts or beliefs, nor is it a list of rules to be followed blindly. It is a dynamic process that constantly evolves as new evidence and knowledge are discovered.
18.
The work of a scientist usually begins with
Correct Answer
B. Careful observations
Explanation
The work of a scientist usually begins with careful observations. This is because observations help scientists gather data and information about a specific phenomenon or problem. By carefully observing and noting down details, scientists can identify patterns, trends, or anomalies that may lead to the formulation of a hypothesis. Careful observations also allow scientists to gather evidence and make informed decisions about the next steps in their research, such as designing experiments or drawing conclusions based on their findings.
19.
Information gathered from observing a plant grow 3cm over a two-week period is called
Correct Answer
D. Data
Explanation
The information gathered from observing a plant grow 3cm over a two-week period is referred to as data. Data is the collection of facts, statistics, or information that can be analyzed to draw conclusions or make interpretations. In this case, the measurement of the plant's growth is a concrete piece of information that can be used to analyze the plant's progress and draw conclusions about its growth rate.
20.
Based on your observations, you suggest that the presence of water could accelerate the growth of bread mold. This is
Correct Answer
B. A hypothesis
Explanation
The given statement suggests that the presence of water could accelerate the growth of bread mold. This is a hypothesis because it is a proposed explanation or prediction based on observations and prior knowledge. A hypothesis is a testable statement that can be supported or refuted through further investigation or experimentation. In this case, the suggestion that water could accelerate the growth of bread mold can be tested by conducting experiments to observe the growth of bread mold in the presence and absence of water.
21.
During a controlled experiment, a scientist isolates and tests
Correct Answer
D. A single variabls
Explanation
During a controlled experiment, a scientist isolates and tests a single variable. This means that the scientist manipulates and observes only one factor or condition while keeping all other variables constant. By doing so, the scientist can accurately determine the effect of the specific variable being tested on the outcome of the experiment. This approach helps in establishing cause-and-effect relationships and drawing valid conclusions based on the obtained results.
22.
A personal preference or point of view is
Correct Answer
A. A bias
Explanation
A personal preference or point of view can be considered a bias because it reflects a subjective judgment or inclination towards a particular belief or opinion. Biases can influence the way individuals perceive and interpret information, often leading to a lack of objectivity and potential distortions in their thinking or decision-making processes.